1. Preheat oven to 400 degrees. Spray 9x13" baking dish with cooking spray, set aside. Break spaghetti into pieces, cook according to package directions, then drain and set aside to cool.
3. Add cooked spaghetti and stir to combine. Spread spaghetti mixture evenly in the bottom of the prepared baking dish. Bake for 15 minutes, then remove and reduce oven temperature to 350 degrees.
5. Bake for 30 minutes, until cheese melts and pasta is heated through. Makes 10 servings.